A realtime system means its deterministic, it means you should know how long things take to run. They way to do is is to apply a patch to the linux kernel that makes it non-preemptible. To explain – Preemption is the act of temporarily interrupting a task being carried out by a computer system, without requiring its cooperation, and with the intention of resuming the task later.

This is useful for building hardware and robotics, low latency audio and other gpio because there are no surprises when it comes to timing. It seems like something good to try out with the RaspberryPi, because of the GPIO and IOT capabilities.

Bundled with CustomPiOS you can build your customized realtime-kernel device.

Features

Both armv6 and arm v7 are supported! Aka all versions of RaspberryPi to date!

4.9.52-rt37-v7 with PREEMPT kernel

Easy way to set up the network using realtimepi_wpa_supplicant.txt in the boot partition